Coupling this assay with the apoptosis tracker, we observed an increase in apoptosis for EXO1 and FANCG double KO cells (Fig. 2d), as well as for double KO cells of EXO1 and FANCM complex factors (FAAP24 and APITD1), and BRCA1-A complex factor FAM175A (Supplementary Fig. 5c–e), demonstrating that the observed synthetic lethal phenotypes trigger cell death by apoptosis, which is a critical finding in defining the suitability of EXO1 as a target in cancer therapy. This evidence concerns the gene BRCA1 and cancer.